Long Transactions in GIS
CHEN Bo~ 1,3 , ZHOU Shun-ping~ 2,3 , WAN Bo~ 2,3 , YE Ya-qin~ 2,3 1.Graduate School, China University of Geosciences, Wuhan430074, China 2.Faculty of Information Engineering, China University of Geosciences, Wuhan430074, China 3.Wuhan Zondy Cyber-Tech Co., Ltd., Wuhan430074, China
This paper offers a solution to the application of a GIS system based on relational database management system (RDBMS) in a given circumstance which requires a long transaction. The traditional method to long transaction is to add locks on data in order to let someone edit it exclusively. That is to say, data can not be edited by more than one person at the same time with the traditional method. The paper starts from the requirement from GIS to long transaction and the questions which went on when people deal the long transaction with the traditional method. A feasible solution is offered which treats a data change as a statement and mark changes in data by state ids, then uses two algorithms to control the statements. With this solution not only data can be edited by few persons synchronously but also the different changes made by different people can be saved respectively.